Mold for composite steel castings.



A. ROJEKOFF.

MOLD FOR COMPOSITE STEEL CASTINGS.

APPLICATION FILED JULY 24,1914.

1,155,510. Patented Oct. 5,1915.

WITNESSES [ACTOR MXMXA,

v ATTORNEY COLUMBIA PLANOGRAPH C0-.WASHINGTON, D. c.

Original application filed September 18, 1912, Serial No. 720,953.

Serial No. 852,819.

ALEXANDER noJnKorr, or BIEJITZA, RUSSIA.

MOLD FOR COMPOSITE STEEL CASTINGS.

To all whom it may concern Be it known that I, ALEXANDER RoJnKorr, a subject of the Emperor of Russia, residing at Biejitza, Russia, have invented certain new and useful Improvements in Molds for Composite Steel Castings, of which the following is a specification.

My invention relates to steel castings, com posed of a plurality of various layers of steel, that is, layers having a different chemical composition, such asdescribed in my application, Serial No. 720,953, filed September 18th, 1912, of which application this application is a division.

The particular object of this invention is to provide means for producing castings of this kind, which are not only free from blow holes, cracks or other defects, but in which the various layers are strongly bonded to gether.

In making castings of this kind, I use a mold of any desired contour according to the required contour of the casting to be made, which mold is divided by one or more partitions into two or. more separate independent compartments. In making composite castings of this kind, one must take into consideration the fact the the liquid molten metal, after ithas been poured into the mold, contracts upon cooling, while the partition or partitions, as the liquid molten metal comes in contact with them, expands. If, therefore, the dimensions of the partitions are such as to exactly correspond to the proportions of the mold, it is inevitable that a rupture of the mold occurs at the place or places where the partitions touch the inner walls of the mold. As a result the parti tions forming part of the finished casting will, due to their expansion, project beyond the contour of the casting. whereby the casting, of course, is spoiled. The partition or partitions, therefore, according'to my invention are made of such a width that a small space remains between the edges of the partition or partitions and the inner walls of the mold and, in order to increase the bonding of adjacent layers and thereby make the casting more solid, I provide pins, hooks or the like, which are placed in the partitions so as to project on both sides thereof.

In the drawing I have shown in horizon tal view, for the purposes of illustration, a mold with one partition placed therein.

The mold which, according to the usual Specification of Letters Patent.

Patented @et. 5, 1915. Divided and this application filed J'uly methods, may be formed in sand or similar material, is designated by the numeral 1, whereas, the partition placed in the mold is marked 2. The partition, as clearly shown in the drawing, is of less width than the distance between the two inner walls of the mold between which walls, the partition is placed, the edges of the partition, therefore, remaining out of contact with the said inner walls, leaving a narrow space, allowing the partition to expand in both directions upon coming in contact with the hot molten metal. The partition should have a certain thickness, determined both by the temperature of the molten metal and the cross section of the cast product. If the partition does not have the proper thickness, the liquid molten mass poured into the mold will, either melt the partition and mingle with the molten mass entering the adjacent compartment, or, if the partition is too thick, it will not, as it should, properly fuse with the liquid molten mass, in which case, of course, the casting will not be a uniformly fused mass. In order to obtain a perfect casting, I prefer to make the partitions of a thickness of no less than 1% and no more than 3.8% of the cross section of the entire casting. The mold, as shown in the drawing, is divided by the partition'2 into two compartments A, B and, as shown, the two edges of the partition are reduced in thickness so that the partition, upon coming in contact with the hot metal, not only can freely expand, due to the spaces left between the edges of the partition and the inner walls of the mold, but also the partition can uniformly combine with the liquid molten mass in both compartments, not withstanding the fact that the walls of the mold have a strong cooling effect on the liquid molten mass.

It is, of course, a matter of great importance in the making of composite castings of this kind that the partitions between the compartments adapted to receive molten steel of different chemical compositions should completely fuse with the molten mass in both compartments therebv effecting a secure bonding of the two different layers. In order to strengthen this bond, I provide the partitions with a plurality of pins, hooks, or the like. marked 3, of iron or steel projecting on both sides of the partition. The use of such pins, hooks, or the like, is con sidered of special advantage in the making of castings of special shapes, such, for instance, as shown in the drawing, which castings shall not be subjected to further treatment, such as hammering, rolling, etc., and, therefore, are made more solid.

The partition, or partitions, if more than one are used, may be suspended from rods placed on the mold, or they may be supported by any other suitable overhead device, such as will readily suggest itself to one skilled in the art.

While I have shown a construction of the mold used in making a composite casting, in

' accordance with my invention, I wish it eX- pressly to be understood that I do not limit myself to this particular construction, but may use molds of any desired contour and also may use, instead of one partition, two or more partitions, thereby increasing the number of compartments and the number of Gopies of this patent may be obtained for different layers of which a finished casting is made. 7

I claim': V I V In a mold for producing composite metal castings made up of layers of different chemical compositions, the combination with the moldof any number of metal partitions adapted to fuse with the hot molten metal and of less width than the opposed walls of the mold bordering the edges of the partition and provided with projections to facilitate and strengthen the bonding of adjacent layers. 7 V

In testimony whereof I have affixed my signature in presence of two witnesses.

ALEXANDER ROJEKOFF.

five cents each, by addressing the Commissioner of Patents, Washington, I). G. r 

